Stretchy e-tattoo measures ECG and SCG heart activity

The graphene-based device is the just the latest incarnation in flexible, wearable cardio electronics to come from the university’s Cockrell School of Engineering, led by Nanshu Lu. According to the researchers, the e-tattoo is the first of its kind to measure electrocardiograph (ECG) and seismocardiograph (SCG) activity, taking both readings simultaneously. It is described in the journal Advanced Science.

While many will be familiar with ECG technology, SCG is less pervasive. It measures vibration in the chest as the heart beats and provides a form of validation for ECG data when the two readings are combined.

"We can get much greater insight into heart health by the synchronous collection of data from both sources," said Lu, an associate professor in the departments of Aerospace Engineering &Engineering Mechanics, and Biomedical Engineering.

Although soft e-tattoos for ECG are not new, SCG sensors are largely still produced using rigid materials, making them bulky and uncomfortable to wear. Lu and her team's e-tattoo is made from a piezoelectric polymer called polyvinylidene fluoride, capable of generating its own electric charge in response to mechanical stress. The device also includes 3D digital image correlation technology that is used to map chest vibrations in order to identify the best location on the chest to place it.